I was driving in the opposite direction from a moving train that had
many cars behind the locomotive. It took me approximately 2-3 minutes
from the time my car 'met' the front of the train until it passed me
going the opposite direction. My speed was about 40 miles an hour. Is
it possible to estimate the length of this moving train without
actually measuring when it is not moving?

Baby mice can breed when they are 6 weeks old and the babies are born
after 3 weeks. If each mother mouse has only one litter and all the
litters have 8 babies, half males and half females, how many mice will
you have 18 weeks from today?

Bill, Simon, and John are brothers. Bill is as many years younger than
one brother as he is older than the other. Simon is 7 years younger
than twice the age of John. John is 5 years older than half the age
of one of his brothers. I keep getting -3 for Simon's age. What am I
doing wrong?